Re: [cc65] linker cfg files

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From: Ullrich von Bassewitz (
Date: 2003-04-22 22:08:21


On Sun, Apr 20, 2003 at 05:11:25PM +0200, 3843416 wrote:
> i have a problem with a specific linker config.
> i want to display grafic on the screen, so i want to reserve memory for
> the bitmap.
> i want to reserve this 8000 bytes at the adress $2000. so i wrote
> following linker cfg:

There are several problems with this config:

  1. The LOWCODE segment is missing.

  2. Segments of type BSS aren't written to the output file. This means that
     the resulting file cannot be just loaded into memory and run, because
     the RAM data, which starts at $3f3e is at the wrong location.

  3. malloc() doesn't reserve use memory from BMP. In fact, it doesn't know
     about BMP and will just ignore it.

One very simple solution would be to change the type of the segment from bss
to rw. This means that the resulting output file will have 8K of zeroes
somewhere in between and will be quite large, but at least it should work.

Groepaz suggestion (placing the hires screen below the kernal ROM) is well
worth a try. The TGI driver for the C64 does it this way (the color RAM goes
below the I/O area) which has the advantage that it works with the standard
memory config, and doesn't use one byte of additional memory.



Ullrich von Bassewitz                        
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